WO2007134370A1

WO2007134370A1 - Cannula for performing aspiration of tissue further comprising imaging device or distal cutter

Info

Publication number: WO2007134370A1
Application number: PCT/AU2007/000659
Authority: WO
Inventors: Andrew Le
Original assignee: Bhc Pharmaceuticals Pty Ltd
Priority date: 2006-05-18
Filing date: 2007-05-16
Publication date: 2007-11-29

Abstract

A cannula for conducting surgical procedures at a surgical site of a patient, the cannula (10) comprising, a generally elongate tubular body (20) having a distal end (22) locatable at or adjacent tissue at the surgical site within the patient, a proximal end (24) engageable with a vacuum source and/or an infiltration fluid source, a passage (26) providing fluid communication between the distal end (22) and the proximal end (24), an inlet to the passage (26) at or adjacent the distal end (22) and an outlet from the passage (26) at or adjacent the proximal end (24), the cannula (10) further comprising an image acquisition means (30) disposed within the passage (26) at or adjacent the distal end (22), wherein said image acquisition means (30) is adapted to provide an image of tissue at or adjacent the distal end (22) of the cannula (10) when located at the surgical site within the patient.

Description

CANNULA FOR PERFORMING ASPIRATION OF TISSUE FURTHER COMPRISING IMAGING DEVICE OR DISTAL CUTTER

Field of the invention

The present invention relates to a device for separation, ablation or removal of body tissue from the body of a patient. In particular, the present invention relates to a device for ablation and removal of subcutaneous fat tissue from the body of a patient, and separation of tissue for surgical procedures, including implanting prostheses.

Background of the invention

Liposuction, also termed liposculpture, is at present one of the most popular cosmetic surgical procedures. Liposuction typically involves the removal of subcutaneous body fat deposits from a patient predominantly for cosmetic purposes such as removal of thigh and buttock fat, stomach reduction, hip and waist reduction, as well as facial procedures including removal of fat deposits from chin, neck, cheek and eye areas of a patient. As well as excess fat removal, liposuction or liposculpture techniques may be used for contouring or sculpturing a patient's body to particular specifications by subtle removal, insertion and/or re-shaping of subcutaneous fat by use of specialised surgical equipment.

The most common form of liposuction is termed "Tumescent" or "Infiltration" liposuction, whereby a fluid known as "tumescent fluid" which consists of a saline solution including adrenaline and lidocaine, is infused or infiltrated within a subcutaneous fat deposit at a surgical site within the body of a patient typically with a blunt needle or an infiltration-type cannula. The infiltration fluid provides localised anaesthesia to the patient so as to reduce pain experienced by the patient whilst also acting as a vasoconstrictor so as to reduce bleeding and internal bruising. The infiltration fluid also stiffens the fat tissue so as assist in the fat removal process.

Once the fat tissue is sufficiently infiltrated, an aspiration cannula is introduced to the subcutaneous region of infiltrated fat tissue and a vacuum is applied to the proximal end of the cannula so as to cause the fat tissue to be sucked into the cannula through apertures located at the distal end of the cannula. In order to break the fat tissue within the cannula from the remaining fat tissue so as to allow the fat to be aspirated from the patient, a surgeon moves the cannula back and forth along the axis of the cannula so as to cause the fat to be dissociated from the remaining fat and thus be removed under vacuum to waste.

The surgeon typically uses tactile sensation on the outer surface of the skin of the patient adjacent the surgical site and, through knowledge of adjacent anatomy, moves the aspiration cannula back and forth and about the surgical site so as to remove the required fat tissue whilst avoiding damaging vital organs, muscle tissue and the like.

A disadvantage associated with present liposuction techniques includes poor or inadequate infiltration of the fat tissue at the surgical site which results in incomplete removal of fat due to resistance of the fat tissue to be removed, and which may cause regions or pockets of infused fat which are difficult to remove. Difficulty of fat removal and increased force or manipulation of the cannula causes localised trauma to the patient which results in increased pain, possible bleeding as well as incomplete removal of unwanted fat thus resulting in an imperfect procedure and result.

Another disadvantage associated present liposuction techniques includes potential for damage to important and vital internal structures such as muscle, nerves and blood vessels. Further, even minor trauma causes intraoperative and post operative discomfort to be suffered by the patient. Furthermore, due to a high level of intraoperative care and precision being required from both safety and efficacy standpoints, liposuction is often a slow and laborious task, requiring significant intraoperative time, often up to many hours in an operating theatre.

Other surgical procedures, for example the implantation of prostheses such as breast implants, require a cavity or pocket to be created at a surgical site within a patient. The creation of this cavity by conventional means can often cause significant trauma to a patient and extend the time required for healing and mobility of a patient. The present invention seeks to overcome or substantially ameliorate at least some of the disadvantages and deficiencies experienced in surgical procedures when using techniques of the prior art.

It will be understood that any references to existing procedures and/or documents are not to be taken as an admission regarding the common general knowledge of a person skilled in the art.

Summary of the invention

In a first aspect, the present invention provides a cannula for conducting surgical procedures at a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end beatable at or adjacent fat tissue at a surgical site within a patient, a proximal end engageable with a vacuum source and/or an infiltration fluid source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end;

an image acquisition means disposed within the passage of the tubular body at or adjacent the distal end, wherein said image acquisition means is adapted to provide an image of tissue at or adjacent the distal end of the cannula when located at a surgical site within a patient.

Preferably the image acquisition means is an arthroscopic camera which is adapted to provide an image of said tissue upon a visual display unit.

A distal cutting tip may be located at the distal end of the tubular body, wherein said distal cutting tip is shaped to facilitate advancement of the cannula through tissue of the patient. Preferably the distal cutting tip is adapted to be retracted at a location external of the surgical site. The inlet may comprise one or more apertures formed in the side of the tubular body adjacent the distal end

Preferably the number of apertures provided is in the range of from 2 to 15, more preferably in the range of from 4 to 12 and still more preferably in the range of from 6 to 9.

Preferably, the apertures have a diameter in the range of from 0.5 mm to 2.5 mm, more preferably in the range of from 0.75 mm to 2.0 mm and still more preferably in the range of from 1.0 mm to 1.5 mm.

Preferably, a suitable number and size of apertures is provided for both infiltration and aspiration of fat tissue.

The tubular body is preferably of circular cross section and has an outer diameter in the range of from 2.0 mm to 4.0 mm, more preferably in the range of from 2.5 mm to 3.5 mm. Preferably the passage has a diameter in the range of from 1.5 mm to 2.5 mm.

The image acquisition means is preferably an arthroscopic camera having a diameter of about 1.0 mm.

The tubular body preferably has a length in the range of from 200 mm to 400 mm, more preferably in the range of from 250 mm to 350 mm.

Preferably, at least one aperture is provided with a peripheral cutting surface for severing of fat tissue drawn into the passage under vacuum. The fat tissue is preferably severed by axial reciprocation of the tubular body.

At least a portion of the tubular body adjacent the periphery of at least one aperture preferably extends radially outwardly so as to form a rasp arrangement for severing of fat tissue at least partly drawn into the passage under vacuum.

Preferably the tubular body is of a suitable curved arrangement to allow for introduction of the distal end to a subcutaneous surgical site. In a second aspect, the present invention provides a cannula assembly for a cannula for conducting surgical procedures a surgical site of a patient, said cannula assembly comprising:

a cannula according to the first aspect; and

a handle means engageable with the proximal end of said cannula.

Preferably the handle means provides fluid communication between a vacuum and/or infiltration fluid supply and the cannula. The handle means preferably provides communication between the image acquisition means and a visual display unit. Preferably the handle means includes an image control means for controlling the optical parameters of the image acquisition means, preferably the light intensity and/or focus of the image acquisition means.

In a third aspect, the present invention provides cannula for a cannula for conducting surgical procedures at a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end beatable at or adjacent fat tissue at a surgical site within a patient, a proximal end engageable with a vacuum source and/or an infiltration fluid source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end; and

a severing means disposed within the passage of the tubular body, said severing means including at least one cutting portion and being movable within the passage from a first position to at least a second position such that fat tissue drawn into the passage upon application of vacuum at the proximal end is severed upon movement of the cutting portion from the first position towards the second position.

Preferably the severing means comprises a frame structure forming cutting portions which pass across the apertures upon moving from the first position towards the second position. The frame structure may move in a rotational direction about the axis of the tubular body when moving from the first position towards the second position. Alternatively, the frame structure moves in an axially direction along the axis of the tubular body when moving from the first position towards the second position.

The cannula preferably further comprises an image acquisition means disposed within the passage at or adjacent the at least one aperture, said wherein said image acquisition means is adapted to provide an image of tissue at or adjacent the distal end of the cannula when located at a surgical site within a patient.

In a fourth aspect, the present invention provides a cannula for delivery of fat tissue to a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end locatable at or adjacent a surgical site within a patient, a proximal end engageable with a fat tissue supply source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end;

Preferably, the fat tissue is provided is autologous.

Preferably, the cannula according to the present aspect may be used for fat grafting at a surgical site within the body of the patient, and the image acquisition means allows for view of the surgical site during delivery of fat tissue to the delivery site.

In a fifth aspect, the present invention provides a cannula for delivery of therapeutic substances to a surgical site of a patient, said cannula comprising: a generally elongate tubular body having a distal end beatable at or adjacent a surgical site within a patient, a proximal end engageable with a therapeutic substance supply, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end;

The therapeutic substance supply source may contain substances including pharmaceutical, antibiotic, steroid and the like substances.

In a sixth aspect, the present invention provides a cannula for dissection of tissue at a surgical site of the patient, said cannula comprising:

a generally elongate tubular body having a distal end beatable at or adjacent a surgical site within a patient, a proximal end engageable with a fluid supply source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the distal end;

A further aspect of the invention provides a method of conducting a surgical procedure which includes the steps of creating a cavity in soft tissue of a patient, introducing a transparent liquid into the cavity, introducing an image acquisition means into the cavity, and, conducting a surgical procedure within or adjacent the cavity whilst observing the procedure by viewing images obtained by the image acquisition means. In an embodiment of the present aspect, a suitable fluid supply source is provided such that the cannula may by used for hydraulic dissection of the tissue of the patient. The cannula may be used for blunt and/or sharp dissection of tissue at the surgical site.

Brief description of the drawings The invention now will be described, by way of example only, and with reference to the accompanying drawings in which:

Figure 1a shows a distal end side view of a first embodiment of a cannula according to an embodiment the present invention;

Figure 1 b shows the embodiment as depicted in Figure 1a in an extended configuration;

Figure 1c shows a cross-sectional view of the cannula as depicted in Figure 1c from above;

Figure 2a shows a distal end side view of a second embodiment of a cannula according to the present invention;

Figure 2b shows the embodiment as depicted in Figure 2a in an extended configuration;

Figure 2c shows a cross-sectional view of the cannula as depicted in Figure 2c from above;

Figure 3a shows an enlarged plan view of the cannula as depicted in Figure 2b from below;

Figure 3b shows an enlarged plan view of the cannula as depicted in Figure 2b from above;

Figure 3c shows a view of the cannula of Figures 3a and 3b from below; Figure 4 shows an illustrative depiction of a cannula according to the present invention in communication with a liposuction system;

Figure 5 shows an illustrative depiction of a handle according to the present invention;

Figure 6a shows a side view of the handle of Figure 5 coupled with another embodiment of a cannula according to the present invention;

Figure 6b shows a side view of the handle of Figure 5 coupled with a further embodiment of a cannula according to the present invention;

Figure 7a shows a first embodiment of a distal cutting end of a cannula according to the present invention;

Figure 7b shows a second embodiment of a distal cutting end of a cannula according to the present invention;

Figure 8 depicts an enlarged view of the distal cutting end of Figure 7a in use; and

Figure 9 depicts an enlarged view of the distal cutting end of Figure 7b in use.

Detailed description of the embodiments

The following description refers to preferred embodiments of a system and method according to the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings whereby the system and method are illustrated in preferred embodiments. Similar components between the embodiments are identified by the same reference numerals.

Referring to Figures 1a, 1 b and 1c, there is shown a view of the distal end of a cannula 10 for aspiration and/or infiltration of fat tissue of a patient according to an embodiment of the present invention. The cannula 10 is for use in liposuction or liposculpture procedures within subcutaneous fat deposits of a patient. The cannula 10 includes a tubular body 20 having a distal end which is beatable at or adjacent fat tissue within the body of a patient, and a proximal open end 24 which is engageable with a vacuum and/or infiltration fluid source. A passage 26 extends between the distal end 22 and the proximal and 24 providing fluid communication between the ends 22, 24. Apertures 28 are provided at the distal end 22 of the cannula 10 and extend through the tubular body 22 so as to provide fluid communication between fat tissue adjacent to the distal end 22 and the proximal end 24 of the cannula 10 to allow for aspiration of body fat from a surgical site of a patient.

An image acquisition means 30 is located within the passage 26 of the tubular body 20 of the cannula 10. The image acquisition means 30, in the present embodiment, is an arthroscopic or endoscopic camera, and is adapted to provide an image of tissue adjacent to the distal end 22 to a surgeon performing an aspiration procedure upon a patient. The image acquisition means 30 typically acquires an image which is viewable upon a visual display unit within an operating theatre, such as a monitor used in arthroscopic or endoscopic procedures. The image acquisition means 30 includes a lens or camera portion 32 which is located adjacent to an aperture 28a which is positioned at the distal end 22 of the cannula 10.

The present embodiment as depicted is provided with a suitable number and size of apertures 28 so as to allow the cannula to be used for both infiltration of fat tissue with an infiltration fluid such as tumescent fluid, and also for aspiration or removal of fat tissue from the body of the patient. The cannula 10 is further provided with a distal cutting tip 21 extending from the tubular body 20 of the cannula 10 in a distal direction.

The cutting tip provides assistance during infiltration of tissue and may be optionally retractable such that the cannula 10 is a blunt-dissection type instrument.

Infiltration of fat tissue during liposuction procedures is typically performed using external tactile sensation of the surgeon's fingertips and is a procedure which requires care and knowledge of adjacent anatomy so as not to cause internal trauma or damage to the patient. Rather than using a sharp needle, infiltration is typically effected in the prior art using a blunt needle so as to avoid injury to internal organs of the patient. Use of a blunt needle rather than a sharp needle increases discomfort to the patient due to blunt dissection and also causes increased difficulty of infiltration in comparison of when a sharp needle is used. Furthermore, the conventional tissue infiltration techniques often result in missed areas or "blind pockets" of target tissue due to the surgeon having to move the needle blindly under the skin of the patient. These blind pockets often cause intra-operative discomfort or pain to the patient due to increased trauma to adjacent tissue as the fat tissue to be aspirated is not completely or effectively infiltrated.

As the cannula 10 of the present invention provides for subcutaneous visualisation of adjacent tissue by the presence of the image acquisition means 30, a surgeon can observe the internal anatomy and organs of a patient, thus sharp dissection may be effected safely by the cannula 10 with the distal cutting tip 21 provided.

Further, by providing direct vision to a surgeon whilst performing the infiltration process of liposuction, the cannula 10 according to the present invention allows for rapid, precise and even infiltration of tumescent fluid. Thorough and even infiltration of fat tissue with infiltration fluid provides for more effective:

1. local anaesthesia and reduction of pain during liposuction;

2. vasoconstriction of tissue thus reducing bleeding and bruising of the patient's tissue;

3. hydraulic dissection of fatty tissues;

4. hydraulic elevation of a patient's body tissues;

5. hydraulic magnification of the patient's tissues.

Referring to Figures 2a, 2b, 2c, 3a, 3b and 3c, a second embodiment of a cannula 10 according to the present invention is shown. The second embodiment includes the same features as those as described with reference to Figures 1a, 1 b and 1c, however, a portion of the tubular body 20 adjacent the apertures 28 extends outwardly so as to form a cutting surface and collectively a rasp arrangement which can be used to sever fat tissue by moving the cannula 10 backwards and forwards along its longitudinal axis. Again, an image acquisition means is provided to allow a surgeon to ascertain the surrounding anatomy of the distal end 22 of the cannula 10 so as to prevent accidental damage of organs and vital anatomy. Again, axial motion of the cannula 10 allows fat tissue induced within the passage 26 of the catheter and to be severed from the remaining tissue external of the catheter 10.

The cannulas of both the first and second embodiments discussed above are provided with suitable numbers and sizes of apertures in order to provide for ablation of fat tissue during liposuction procedures. The first embodiment as referred to in Figures 1a, 1 b and 1c, is suitable typically for more conservative liposuction procedures, whereas the second embodiment as described with reference to Figures 2a, 2b, 2c, 3a, 3b and 3c, is typically used for more aggressive liposuction procedures whereby a more aggressive surgical procedure is required to remove fat tissue from the body of a patient.

The cannula 10 of the first embodiment typically has about 9 apertures located at the distal end 22 for cutting and infiltrating fat tissue, the apertures having a diameter of about 1 mm. The cannula 10 has a length of about 250mm, an external diameter of about 2.5mm, a wall thickness of about 0.25mm and an image acquisition means in the form of an arthroscopic camera having a diameter of about 1 mm and located inside the internal passage 26.

In the second embodiment, the more aggressive version of the cannula 10 typically has about 6 apertures for cutting and infiltration of fat tissue, an outer diameter of about 3.5mm, a length of about 350mm, an aperture size of 1.5mm, a wall thickness of about 0.5mm and an image acquisition means in the form of an arthroscopic camera having a diameter of about 1 mm.

Referring to Figure 4, there is shown a cannula 10 according to the present invention in conjunction with a fat transfer system 40.

The cannula 10, as provided in the present embodiment, allows for both aspiration and infiltration of fat tissue at a surgical site of a patient, whilst providing direct vision of the location of the distal end 22 of the cannula 10 within the body of a patient via a monitor screen 50. As such, a surgeon using the cannula 10 in conjunction with the system 40, may more effectively infiltrate fat tissue with an infiltration fluid by virtue of being able to visualise tissue and/or organs adjacent to the distal and 22 of the cannula 10. As discussed above, the surgeon is also able to more effectively remove unwanted fat tissue from the body of the patient.

In traditional liposuction procedures, as discussed above, the surgeon performing the procedure relies on "tactile vision" by using a hand touching the skin of the patient from external of the patient to locate the instrument, and has to guess or estimate how much fat under the skin of a particular surgical site needs to be removed or sculptured.

The surgeon also has to rely on knowledge of anatomy to ensure that the distal of the cannula does not hit vital structures such as muscles, nerves, blood vessels, and more importantly avoid potentially lethal complications such as perforation of the abdominal wall or perforation of arteries such as carotid arteries in the neck of the patient. These limitations and potentially serious complications and side effects dictate a slow and laborious liposuction technique, requiring a delicate operation and often taking many hours of time in the operating theatre. These factors may in turn increase:

surgeon fatigue;

• patient discomfort; • increased chance of infection;

• complications;

• poor results or outcomes; decreased accuracy and efficacy of operation.

The present invention, by providing a cannula including an image acquisition means to allow for monitoring of a surgical site by a surgeon, allows the target tissue and the volume thereof, to be removed and shaped as required. Furthermore, the present invention allows a surgeon more confidence in rapid removal of fat tissue and provides for minimisation of risk to damage of adjacent anatomy.

The present invention provides the following advantages:

1 The surgeon may direct the cannula 10 to the target tissue site with ease and confidence, whilst at the same time fat will be drawn into the cannula and removed from the body of the patient;

2 Reduction in:

operation time; • patient intra-operative pain; bruising, bleeding and infection; chance of damage to vital organs and anatomic structures; friction burn of the skin; uneven or poor results; surgeon fatigue and errors; and 3 Increases in: aesthetic outcome; patient satisfaction.

The reduction in intra-operative time as provided by the cannula 10 according to the present invention allows for more expedient recovery post-operatively for the patient, and reduces costs due to reduction in theatre time, theatre equipment and theatre staff.

Referring to Figure 5, there is shown an enlarged view of handle 60 of Figure 4 which is engaged with a cannula 10. The handle 60 allows for adjustment of optical parameters of the image acquisition means, for example, brightness by brightness control 61 , contrast by contrast control 62, focus by focus control 63 and zoom by zoom control 64. In the present embodiment, the cannula 10 is connected to the system 40 of Figure 5 via infiltration fluid conduit 65, an aspiration conduit 66, a light source conduit 67 and an acquisition image conduit 68. It will be appreciated, of course, that other controls may be provided on the handle 60 such as controls for controlling whether the cannula 10 is operated in aspiration mode or infiltration mode.

Referring to Figures 7a, 7b, 8 and 9, a further embodiment of a cannula 70 according to the present invention is shown. The present aspect includes a severing means 72 which is disposed within the passage 74 of the cannula 70 which, when moved relative to the cannula, severs fat 80 which has been drawn into the passage 74 of the cannula 70 via apertures 76 when vacuum is applied to the cannula 70. The embodiment of the cannula 70 as shown in Figure 7a and 8 has a circular cross section and a severing means 72 which, when rotated about the longitudinal axis of the cannula 70, severs fat 80 which has been drawn within the passage 74 through apertures 76 under vacuum as cutting portions 72a of the cutting means 72 rotate past apertures 76.

The embodiment of the cannula 70 as depicted in Figure 7b is of a generally triangular cross section and includes a cutting member 72 which, when moved axially with respect to the longitudinal axis of the cannula 70, severs fat 80 drawn within the passage 74 through apertures 76 under vacuum. In the present embodiment, the cutting means 72 is provided with cutting portions 72a which, when the cutting member 72 is moved axially, travel past the apertures 76 so as to sever the tissue.

The present aspect as described with reference to Figures 7a, 7b, 8 and 9 allows a surgeon to remove fat tissue from the body of a patient without the need to move the cannula axially back and forth as is required with techniques of the prior art. This, as will be appreciate by those skilled in the art, this substantially reduces the chance of accidental severing of vital anatomy or organs and also significantly reduces the amount of effort required by the surgeon during a liposuction procedure, thus reducing fatigue to the surgeon and providing for a superior operation to be performed.

The cannula 70 of the present aspect may, as described with reference to the preceding aspect, include an image acquisition means so as to allow a surgeon to also visualise the adjacent tissue and anatomy when performing a liposuction procedure using cannula 70. It will be appreciated that the present aspect as described may also be used in conjunction with any of the features as described with reference to the previous embodiments, including use of cannula 70 with the system 40 as described with reference to Figure 4.

Various aspects of the present invention as described and claimed provide for a superior liposuction device by providing at least some of the following features in the above embodiments and variations thereof:

subcutaneous visualisation of tissue during infiltration; visualisation of adjacent fat tissue during liposuction; • the use of the same cannula for both infiltration and aspiration of fat tissue; a cannula which need not be axially moved in order to sever fat tissue drawn within the cannula; and any combination of the aforementioned features.

By providing a cannula including an image acquisition means aspects of the present invention allows for monitoring of a fat delivery and/or augmentation site and allows a surgeon to directly view the deposition of fat tissue and thus more accurately deposit fat tissue in required deposition sites. As such, a more well defined and accurate deposition of fat is provides resulting in more satisfactory surgical results.

Still further, by providing a cannula including an image acquisition means a surgeon is able to thoroughly infiltrate tissue at or adjacent a surgical site, thus minimising the likelihood of the occurrence of inadequately anesthetised tissue. This increases patient comfort whilst also allowing for more effective removal of tissue through the cannula. As such, intraoperative bleeding, pain and post operative bruising are substantially reduced and/or minimised.

Furthermore, the present invention allows for spontaneous anaesthetising during surgical procedures, again providing for more effective treatment for a patient by minimising pain and discomfort.

The present invention may also be used as a sharp and/or blunt dissector for forming surgical pockets for prostheses such as breast implants, nose implants, buttock implants, cheek implants and the like. Aspects of the present invention have the advantages of allowing for direct and/or magnified vision during procedures, and allow for hydraulic dissection, a technique more gentle and safe than sharp or blunt dissecting in a dry surgical environment.

In other embodiments, the present invention may be used as a direct vision biopsy device for diagnostic or investigative purposes such as lumbar puncture. In-situ or in-vivo direct viewing and examination of tissue may be provided by the present invention. Viewing of tissue for the examination of abnormal occurrences such as hemarthrosis, removal of lipomata, cysts, tumours may be provided by the present invention.

Still further, the present invention allows for direct vision of delivery of therapeutic substances to many areas of the body including injection of joints steroids, anaesthetics, viscous material, hyaluronic acid, epidural nerve block, chemotherapy and the like.

It will be appreciated that the abovedescribed embodiments may take alternate forms and include additional features which, when used with the present invention, remain within the scope and spirit of the invention as described and claimed.

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.

It will also be understood that the term "comprises" (or its grammatical variants) as used in this specification is equivalent to the term "includes" and should not be taken as excluding the presence of other elements or features.

Claims

1. A cannula for conducting surgical procedures at a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end locatable at or adjacent tissue at the surgical site within the patient, a proximal end engageable with a vacuum source and/or an infiltration fluid source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end;

an image acquisition means disposed within the passage at or adjacent the distal end, wherein said image acquisition means is adapted to provide an image of tissue at or adjacent the distal end of the cannula when located at the surgical site within the patient.

2. A cannula according to claim 1 , wherein the image acquisition means is an arthroscopic camera which is adapted to provide an image of said tissue upon a visual display unit.

3. A cannula according to either claim 1 or claim 2 further comprising a distal cutting tip located at the distal end of the tubular body, wherein said distal cutting tip is shaped to facilitate advancement of the cannula through tissue of the patient.

4. A cannula according to claim 3, wherein the distal cutting tip is adapted to be retractable.

5. A cannula according to any one of the preceding claims, wherein the inlet comprises one or more apertures formed in the side of the tubular body adjacent the distal end.

6. A cannula according to claim 5, wherein the number of apertures provided is in the range of from 2 to 15.

7. A cannula according to either of claims 5 or 6, wherein the apertures have a diameter in the range of from 0.5 mm to 2.5 mm.

8. A cannula according to either of claims 5 or 6, wherein the apertures have a diameter in the range of from 1.0 mm to 1.5 mm.

9. A cannula according to claim 5, wherein the number and configuration of apertures is selected for effective infiltration and aspiration of fat tissue.

10. A cannula according to any one of the preceding claims, wherein the tubular body is of circular cross section.

11. A cannula according to claim 10, wherein the tubular body has an outer diameter in the range of from 2.0 mm to 4.0 mm

12. A cannula according to any one of the preceding claims, wherein the passage has a diameter in the range of from 1.5 mm to 2.5 mm.

13. A cannula according to any one of the preceding claims, wherein the tubular body has a length in the range of from 200 mm to 400 mm.

14. A cannula according to any one of claims 5 to 13, wherein at least one aperture is provided with a peripheral cutting surface for severing of fat tissue drawn into the passage under vacuum.

15. A cannula according to claim 14, wherein at least a portion of the tubular body adjacent the periphery of at least one aperture extends radially outwardly so as to form a rasp arrangement for severing of fat tissue.

16. A cannula according to any one of the preceding claims, wherein the tubular body is of a suitable curved arrangement to allow for introduction of the distal end to a subcutaneous surgical site.

17. A cannula assembly for conducting surgical procedures at a surgical site of a patient, said cannula assembly comprising:

a cannula according to any one of claims 1 to 16; and

a handle means engageable with the proximal end of said cannula, wherein the handle means provides fluid communication between a vacuum and/or infiltration fluid supply and the cannula.

18. A cannula assembly according to claim 17, wherein the handle includes communication means for communication between the image acquisition means and a visual display unit.

19. A cannula assembly according to either one of claims 17 to 18, wherein the handle means includes an image control means for controlling the optical parameters of the image acquisition means,

20. A cannula assembly according to claim 19, wherein the optical parameters controllable by the image control means include the light intensity and/or focus of the image acquisition means.

21. A cannula for conducting surgical procedures at a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end beatable at or adjacent fat tissue at a surgical site within the patient, a proximal end engageable with a vacuum source and/or an infiltration fluid source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the distal end; and

a severing means disposed within the passage of the tubular body, said severing means including at least one cutting portion which is movable within the passage from a first position to at least a second position such that fat tissue drawn into the passage upon application of vacuum at the proximal end is severed upon movement of the cutting portion from the first position towards the second position.

22. A cannula according to claim 21 , wherein the severing means comprises a frame structure forming cutting portions which pass across the apertures upon moving from the first position towards the second position.

23. A cannula according to claim 22, wherein the frame structure moves in a rotational direction about the axis of the tubular body when moving from the first position towards the second position.

24. A cannula according to claim 22, wherein the frame structure moves in an axial direction along the axis of the tubular body when moving from the first position towards the second position.

25. A cannula according to any one of claims 21 to 24, wherein the cannula further comprises an image acquisition means disposed within the passage at or adjacent the at least one aperture, said wherein said image acquisition means is adapted to provide an image of tissue at or adjacent the distal end of the cannula when located at the surgical site within a patient.

26. A cannula for delivery of fat tissue to a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end locatable at or adjacent a surgical site within the patient, a proximal end engageable with a fat tissue supply source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the distal end;

an image acquisition means disposed within the passage of the tubular body at or adjacent the distal end, wherein said image acquisition means is adapted to provide an image of tissue at or adjacent the distal end of the cannula when located at a surgical site within the patient.

27. A cannula according to claim 26, wherein the image acquisition means is an arthroscopic camera which is adapted to provide an image of said tissue upon a visual display unit.

28. A cannula for delivery of therapeutic substances to a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end beatable at or adjacent a surgical site within the patient, a proximal end engageable with a therapeutic substance supply, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end;

29. A cannula for dissection of tissue at a surgical site of a patient, said cannula comprising:

a generally elongate tubular body having a distal end beatable at or adjacent a surgical site within the patient, a proximal end engageable with a fluid supply source, a passage providing fluid communication between the distal end and the proximal end, an inlet to the passage at or adjacent the distal end and an outlet from the passage at or adjacent the proximal end;

30. A method of conducting a surgical procedure which includes the steps of creating a cavity in soft tissue of a patient, introducing a transparent liquid into the cavity, introducing an image acquisition means into the cavity, and, conducting a surgical procedure within or adjacent the cavity whilst observing the procedure by viewing images obtained by the image acquisition means.

31. A method according to claim 30, wherein a suitable fluid supply source is provided such that a cannula may by used for hydraulic dissection of the tissue of the patient.

32. A method according to claim 31 , wherein the cannula may be used for blunt and/or sharp dissection of tissue at the surgical site.